<div dir="ltr">Dear Christophe,<div><br></div><div>Many thanks for your suggestions and guidance.</div><div><br></div><div>I have been working on the issue, but with few improvements: </div><div><br></div><div>- As for the PostOperation in the time harmonic simulation there seems to be no problem. I can successfully create my initial state files with the following code:</div><div><br></div><div>///**********************************************************************************************</div><div><br></div><div> PostOperation Plot_ReaL_Vector_Potential UsingPost MagStaDyn_a_2D {</div><div><span style="white-space:pre-wrap"> </span>// Plotting the Real values of the magnetic </div><div><span style="white-space:pre-wrap"> </span>Print[ az_real, OnElementsOf Region[{ Domain, Rotor_Bnd_MBaux }], Format NodeTable, LastTimeStepOnly,</div><div><span style="white-space:pre-wrap"> </span>File StrCat[ResDir,"TH_Potential_NodeTableFile",ExtTxt]] ;</div><div><span style="white-space:pre-wrap"> </span>// Save the values of the eddy currents in a run time variable ($$)</div><div><span style="white-space:pre-wrap"> </span>Print[ I, OnRegion DomainC, Format TimeTable, </div><div><span style="white-space:pre-wrap"> </span>File > StrCat[ResDir,"TH_current",ExtGnuplot], LastTimeStepOnly,</div><div><span style="white-space:pre-wrap"> </span>StoreInVariable $rotor_current];</div><div><br></div><div>///**********************************************************************************************<br></div><div><br></div><div>- As for the Init Constraint imposition it looks like to be more complicated:</div><div><br></div><div>The following syntax:</div><div><br></div><div>///*******************************************************************************************</div><div><br></div><div> Time_Harmonic_Potential[] = ListFromFile[]{TH_Potential_NodeTableFile.txt} </div><div><br></div><div>///*******************************************************************************************<br></div><div><br></div><div>Is not working whatsoever, even with other sort of sintax like the one I can find at this link: <a href="http://comments.gmane.org/gmane.comp.cad.gmsh.general/5437">http://comments.gmane.org/gmane.comp.cad.gmsh.general/5437</a> . </div><div>Keeps providing a sintax error, no matter what is the file path I am referring to. Furthermore, I unfortunately cannot find references for the ValueFromIndex command. However,until ListFromFile is not working, I sadly cannot move forward.<br></div><div><br></div><div>Regarding the "Init" Constraints, after I add them in the Constraint definition environment, how can I force them only for the first time-domain-step from within the Function spaces definition? Do I have to access another runtime variable, as for instance the TimeStep?</div><div><br></div><div>Do you have any advice or you know what I got wrong?</div><div><br></div><div>Thanks in advance.</div><div>Sincerely,</div><div><br></div><div>Nicola Chiodetto</div><div class="gmail_extra"><br><div class="gmail_quote">On Sun, Mar 27, 2016 at 10:05 AM, Christophe Geuzaine <span dir="ltr"><<a href="mailto:cgeuzaine@ulg.ac.be" target="_blank">cgeuzaine@ulg.ac.be</a>></span> wrote:<br><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex"><br>
Hi Nicola,<br>
<br>
This is indeed a good idea. There are several ways you can impose the initial values. I think that the easiest in your case is to directly specify the constraint (of Init type) in the function space of the relevant quantities (the vector magnetic potential a; as well as the current Iz if you have circuit relations), using a list of values extracted from the first time-harmonic solution.<br>
<br>
(The small technical issue that prevents the use of the classical "TransferSolution" method is that the frequency-domain formulation leads to different degrees of freedom (they are complex) than the time-domain formulation: you can thus not simply transfer values from one system to the other: the unknown vector is different.)<br>
<br>
In order to import list of values for the Init constraint, you could do as follows:<br>
<br>
- perform the time-harmonic simulation, followed by a PostOperation that<br>
- plots the (real part of the) vector potential in the domain, and export it as a "NodeTable" file ("Format NodeTable")<br>
- saves the value of the current in a run-time variable (StoreInVariable $MyCurrent)<br>
- add an "Init" type constraint for the relevant quantities in the function spaces used for the time-domain solution<br>
- for the vector potential, use "Value ValueFromIndex[MyPotential[]], where MyPotential[] = ListFromFile[]{MyNodeTableFile.txt}<br>
- for the current, use "Value $MyCurrent"<br>
<br>
Let us know how this works out. If it works well we might want to add this to the template.<br>
<br>
Christophe<br>
<div><div><br>
> On 18 Mar 2016, at 15:04, Nicola Chiodetto <<a href="mailto:nicola.chiodetto@gmail.com" target="_blank">nicola.chiodetto@gmail.com</a>> wrote:<br>
><br>
> Dear GetDP users and experts,<br>
><br>
> I am willing to simulate an induction motor with time stepping technique.<br>
><br>
> I alredy used and studied the examples provided in the Electrical Machines folder available online.<br>
> However, I need to avoid the initial electrical transient: in other words I need to set proper initial conditions. Since the Induction machines is intrinsically operating due to eddy currents reaction I need to perform a time-harmonic. At this point I was thinking to read the real part of the vector magnetic potential, over all the domains, and take its real part. However, I do not know how to force the conditions of global rotor current variables in the domain bars. Is it possible witout touching the source code?<br>
> Moreover, usually in literature it is proposed a time harmonic frequency analysis exploiting an effective permeability function, instead of a simpler linear one. Is it possible to do that? It could be again useful for determining better initial conditions for the time stepping simulation first point.<br>
><br>
> Thanks in advance.<br>
> Best regards,<br>
><br>
> Nicola Chiodetto<br>
><br>
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University of Liege, Electrical Engineering and Computer Science<br>
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